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Per Phase 1 audit at cowork/docs-overhaul-phase-1-audit-2026-05-04/. Adds a `> Last reviewed: 2026-05-05` line right after the H1 heading of every doc that didn't already have one (41 files). This dates the freshness clock for the future Phase 4 per-doc review. The discipline going forward: when a doc's content gets a meaningful edit, bump the date. When the date gets old (e.g., >6 months), the doc earns a freshness-review pass. Mechanical insertion via awk one-liner, applied to every docs/*.md that didn't already match `grep -q 'Last reviewed:'`. Files that already carried the line from earlier Phase 2 work (the navigation index, the new connector docs, the new SCEP server / legacy-clients- TLS-1.2 / release-verification docs, and the 5 per-connector deep dives) were skipped to avoid duplicate insertion. Net: every doc in docs/ now has a Last reviewed line.
6.9 KiB
certctl for cert-manager Users
Last reviewed: 2026-05-05
You run cert-manager inside Kubernetes and it works well for in-cluster certificates. But you also have VMs, bare-metal servers, network appliances, and legacy systems outside the cluster. cert-manager can't reach those. This guide shows how certctl complements cert-manager to give you unified certificate visibility and automation across your entire infrastructure.
Not a Replacement
cert-manager is the right tool for in-cluster certs. It's tightly integrated with Kubernetes:
- Native CRDs (Certificate, ClusterIssuer, Issuer)
- Automatic cert injection into Ingress and Service objects
- Controller-driven renewal within the cluster
certctl does not replace this. Instead, it extends your certificate management to everything outside Kubernetes: VMs, bare metal, network appliances, Windows servers, and legacy systems.
The Problem
Your setup:
- cert-manager: handles all certs in Kubernetes (TLS for Ingress, service-to-service, internal services)
- Everything else: NGINX/Apache on VMs, HAProxy load balancers on bare metal, network appliances, Windows servers with IIS — these are managed inconsistently. Maybe Certbot cron jobs, maybe manual renewal, maybe deprecated cert files sitting around.
Result:
- No unified visibility — you don't know when non-Kubernetes certs expire
- Renewal failures go unnoticed until the cert is already expired
- Audit trail fragmented across multiple tools
- Scaling to hundreds of machines becomes impossible
The Solution
Deploy certctl control plane once (Docker Compose, Kubernetes Helm chart, or self-hosted). Deploy agents on your VMs, bare metal, and network appliances. One dashboard shows:
- All cert-manager certs via discovery scanning (agents find cert-manager-issued certs copied to target machines, or scan the cluster directly)
- All certctl-managed certs issued by shared issuers (ACME, step-ca, Vault PKI (planned), private CA)
- Unified renewal and deployment across both worlds
- Single pane of glass with expiration timeline, renewal status, deployment verification, audit trail
How to Set Up
1. Install certctl Control Plane
Option A: Docker Compose (quickest for evaluation)
cd /opt/certctl
docker compose up -d
# Dashboard & API: https://localhost:8443 (self-signed cert — pin with --cacert ./deploy/test/certs/ca.crt)
Option B: Kubernetes (recommended for prod)
helm install certctl deploy/helm/certctl/ \
--set auth.apiKey=YOUR_SECURE_KEY
2. Deploy Agents to Non-Kubernetes Infrastructure
On each VM, bare-metal server, or appliance (via proxy agent):
# Linux amd64
curl -sSL https://github.com/certctl-io/certctl/releases/download/v2.1.0/certctl-agent-linux-amd64 \
-o /usr/local/bin/certctl-agent
chmod +x /usr/local/bin/certctl-agent
# Config
sudo tee /etc/certctl/agent.env > /dev/null <<EOF
CERTCTL_SERVER_URL=https://certctl-control-plane:8443
CERTCTL_SERVER_CA_BUNDLE_PATH=/etc/certctl/tls/ca.crt
CERTCTL_API_KEY=your-api-key
CERTCTL_DISCOVERY_DIRS=/etc/nginx/certs,/etc/ssl,/etc/letsencrypt/live
CERTCTL_KEY_DIR=/var/lib/certctl/keys
EOF
sudo chmod 600 /etc/certctl/agent.env
# Start
sudo systemctl start certctl-agent
3. Enable Discovery Scanning
Agents scan configured directories and report back all existing certs. In the dashboard:
- Discovery page: all found certs grouped by agent
- Claim cert-manager certs to link them with Kubernetes metadata
- Dismiss obsolete certs
4. Configure Shared Issuers
Set up the same issuer certctl uses for non-Kubernetes certs:
- ACME (Let's Encrypt, for public certs)
- step-ca (Smallstep, for internal certs)
- Vault PKI (HashiCorp Vault, for enterprise PKI)
- Private CA (your own internal root CA)
No new CA infrastructure needed. If cert-manager already uses your CA, certctl points to the same one.
5. Create Policies for Non-Kubernetes Certs
Go to Policies → + New Policy to create enforcement rules:
- Name: e.g., "VM Certificate Policy"
- Type:
expiration_windoworkey_algorithm(enforce renewal thresholds or crypto requirements) - Severity:
high - Config: set your enforcement parameters
Certificates are linked to issuers and profiles when created or claimed from discovery. Policies add guardrails — enforcing key algorithm requirements, expiration windows, and other compliance rules across your fleet.
6. View Unified Inventory
Dashboard shows:
- Certificate status heatmap (all 1000 certs: cert-manager + certctl)
- Renewal job trends (both types)
- Expiration timeline (30/60/90 days)
- Agent fleet status (all infrastructure)
Certificates page filters by issuer (show me all ACME certs, or all step-ca certs):
- cert-manager certs discovered from Kubernetes nodes
- certctl-managed certs on VMs
- Network appliance certs auto-discovered
Shared Infrastructure
If cert-manager and certctl both use the same CA:
- ACME: cert-manager uses ClusterIssuer + certctl uses ACME connector → same Let's Encrypt account, transparent coexistence
- step-ca: cert-manager uses external issuer CRD + certctl uses step-ca connector → same provisioner, shared certificate inventory
- Vault PKI: cert-manager uses external issuer CRD + certctl uses Vault connector → same mount, same audit trail
No conflict. They just issue certs through the same CA. certctl's discovery scanning finds cert-manager-issued certs and shows them alongside certctl-managed ones.
Key Differences from cert-manager
| Feature | cert-manager | certctl |
|---|---|---|
| Target | In-cluster (Kubernetes) | Out-of-cluster (VMs, bare metal, appliances) |
| Configuration | CRDs (Certificate, ClusterIssuer, Issuer) | API + Dashboard (JSON REST) |
| Deployment | Injected into Secret objects, mounted by pods | Agent pulls work, deploys via target-specific API (file, service restart, proxy agent) |
| Renewal | Controller watches Certificate CRDs, triggers renewal when needed | Scheduler checks thresholds, agents poll for work |
| Audit | Kubernetes event log | Immutable append-only audit trail |
| Visibility | Per-namespace, per-resource | Fleet-wide, unified inventory |
Future Integration
On the roadmap (V4): cert-manager external issuer — certctl acts as a ClusterIssuer backend for Kubernetes. This would allow cert-manager to request certificates from certctl, which could issue them via any of its connectors (step-ca, Vault, private CA, etc.). Pure integration play; no breaking changes.
For now: cert-manager handles Kubernetes, certctl handles everything else. They coexist seamlessly.
Next Steps
- Run through the Quick Start for a 5-minute demo
- Try the Multi-Issuer example — manages public and internal certs from one dashboard
- Explore Architecture for deployment patterns
- Check the Helm Chart for production Kubernetes deployment